How Does a Heart Beat?
by snowfuzz
Summary: After Gumball gives Fionna an impossible task with no escape, what will she do? She finds herself in an uncomfortable situation that means sacrificing someone very dear to her... and killing someone who's falling hopelessly in love with her. - Sorry for the awful description. I love you if you read it, I love you if you don't. And sorry for the nickname typos.
1. The Impossible Task

**FIRST AT FANFIC! Ah, wish me luck! :3 BTW, this is a kind of dark story, thus the T rating. Hope you enjoy it, though! Feedback would be fantastic! Try and make it positive a leeeetttle bit, please? Love you guys!  
xoxo,**

**Snowfuzz**

* * *

"Fi-ONNA! Let's hurry up! Prince _Guuuuuuuuumball_ is waiting at the castle for you! Come on!"

I sat up, drool dribbling down my chin. I wiped it off and stumbled out of bed. I yawned as I made my way down the ladder and towards Cake. I smiled wearily at her and mumbled, "Morning."

She rolled her eyes and stretched her arm upstairs. When it came back, she slapped my hat onto my head and shoved me onto her back. "Come on, now! We're already late!"

I barely had time to grab on before Cake sped out the door, transforming into a bigger version of herself and galloping off.

"WOAH!" I shouted, now fully awake. Anyone should be fully awake after almost flying off an eight foot version of your cat. I managed to not fall off for the rest of the ride. Cake slowed down as we reached the gate of the Candy Kingdom where a pink man and his unicorn-horse-like companion stood waving at us. I jumped off the now-shrinking Cake and ran over to them, my friend following closely behind me.

"PB! What's happening?"

He looked serious, like someone was just murdered. "Fionna, I need to talk to you in private."

Cake raised an eyebrow at me and I shrugged. She leaned over and whispered, "If anything happens, just scream and I can punch the living daylights outta him."

I shooed her away with Lord Monochromicorn and turned back to Gumball. I shrugged at him and gave him a little smile. He didn't return it.

"Fionna," he said, looking kind of disturbed. He paced through the hedge maze of his garden, back to me, eyes on the ground.

"Y-Yes?"

He stopped, and I almost crashed into him. What was he doing? He finally turned around and looked me in the eye. His eyes held no warmth and sent chills up my spine. What the…?

"I need you to kill Marshall Lee."

Marshall Lee was the King of Vampires. He was untouchable. He was also my friend. Sure, he pissed me off and I would punch him really hard, but to kill him was a bit too much.

"_Kill _Marshall Lee?!" I backed away from Gumball, his eyes still staring at me. He advanced with every step I took. I tripped into a bush and Gumball cornered me. He lowered his face until it was level with mine.

"He has to die."

I tried to push him away, but he wouldn't budge. I suddenly thought back to what Cake had said earlier. So I opened my mouth and screamed.

"WHAT ARE YOU DOING TO MY BABY?!"

I glanced up at a ten foot Cake trampling her way to us. Gumball was still in my personal space, and he refused to back off. What was wrong with him?! Cake reached down to pick me up, but Gumball drew out a FREAKING SWORD and pointed it at my throat.

"No." He said, his face still creepily unreadable.

WHO DID HE THINK HE WAS?!

He looked over to me and said, "I need you to kill Marshall Lee, Fi. This is important that he's dead. And soon. He's evil, okay? I don't want him hurting you, Fionna."

I backed up as much as I could into the bush. He was starting to creep me out. "HIM HURTING _ME?! _HAVE YOU SEEN YOURSELF LATELY? WHAT THE HECK IS WRONG WITH YOU?!"

Gumball's expression didn't waver. He narrowed his eyes and said, "Do it, or you and your cat here may not be the only ones getting killed."

My eyes widened. How had this gentle, loving, caring man turn into such a hideous beast? I gulped and finally gave in.

"I- I guess I have to do it."

Gumball smiled at me. But the smile had no warmth. "I want you to say it. Those five words. Right now. And make a _royal promise_."

"I-I make a royal promise that… I will kill Marshall Lee."

Gumball lowered the sword, and I relaxed a little bit. He tilted his head and muttered, "I'll be nice and give you all the time you need. But if you forget…"

He raised his sword and held it against my neck again. He smiled once more and marched away. What did I just throw myself into?


	2. Heart Beats

**Uhhh, sorry if the story plot moves too fast. Thanks for anyone who reads this, I guess :3**

**xoxo,**

**Snowfuzz**

* * *

"What the heeeeeeeeck?!" I groaned as I collapsed on the couch.

"Do you want me to make you some of my famous hot cocoa?" Cake put a comforting hand on my back. She patted my head as I nodded miserably. What the heck was wrong with Gumball?! He never acts like this! And what happened with Marshall Lee? Kill him? He's not _that_ evil! Besides, how do you kill someone who's already dead? I groaned into the couch once more and listened to Cake hum a quiet melody that greatly calmed me down.

"Cake?" I called out, finding my voice.

"Yah, sugar?"

"What if I can't do it? He told me that we wouldn't be lucky if I didn't follow through."

She sighed and looked over at me. "Oh, honey, I wouldn't give it too much thought right now. I agree, though. There's no way I could kill him. I mean, if I weren't dating Monochromicorn, I would be chasing after that-"

I gagged, causing her to erupt in laughter. I smiled a little bit, too. It's not because I thought Marshall Lee was attractive. It's because he was my friend and I didn't want to lose him. He was so cool and even if I want to strangle the crap out of him sometimes, I don't want to be the one who ends him.

"Ooo, did I make you blush just thinking about him?"

I looked up and saw Cake smugly smiling at me. I fell backwards, my face flushing even more. She held two cups and handed one to me.

"Loosen up," she sat down and took a sip. "We can even go see him later, if you want."

I stared into my cup. I felt like that was a really bad idea, but I kind of wanted to see him. I wanted to decide if I was up to this job or not. I finally nodded.

* * *

We approached the little house in the cave and Cake pushed me up on the porch. She punched my arm until I knocked on the door. I finally gave in and tapped on the wooden door. We waited for a minute before a tall, blue-toned, black haired, plaid wearing, jean-ripped, floating guy opened the door. He blinked a couple times, as if he was really confused that we were here.

"Fionna…" he mumbled.

"And Cake!" I squeaked. Suddenly I felt really nervous to be around him.

He nodded and raised his eyebrows at me. He motioned for us to come in, and I followed a trotting Cake into the bright house. I heard the door close behind us, and my heart sped up and I suddenly was aware of a lot of things. He can't know, he can't know, he can't know…

"So, guys, what brings you here?"

I slightly jumped, and turned to find him right in front of my face, his nose brushing mine. I yelped and spun around, holding both of my hands over my nose and mouth.

"Fi?" Marshall flew around me and looked at me. I averted his gaze, my face turning bright red. He reached out a hand, but I ducked out of his reach.

"I can't do it!" I spat out, tears forming in my eyes. Not even five minutes and I was already running out the front door, leaving Cake and Marshall Lee to stare at me in confusion and pain. I'm sorry.

* * *

"Leave me to drown in my own despair." I muttered as I heard a pair of feet approach the viewing boat/ deck on the roof of the house.

"There you are, Fi."

I froze. That voice. It was him. I pulled the blanket up over my head. I couldn't do it. I didn't want to look at him and then kill him. I didn't want to look into his eyes as I brought the blade down and ended him… I pulled the blanket around me tighter.

"Fi? Are you okay?"

"Just go away," I mumbled. Suddenly, my blanket was yanked off. I curled up in a ball, hiding my face with my arms.

"Nuh-uh-uh," I heard him say and then he sat on me!

"Oof!"

"Come on, Fi," He said, poking at my arm. I groaned and rolled over, knocking him off.

I sat up, quickly brushing away the tears in my eyes. Marshall must've notice because he got closer to me. I turned away, getting to my feet and jumping down. I wanted to get away from him. I ran into the house and into my room. I jumped into my bed and wiggled into my sleeping bag, so my feet were at the open end. I heard Marshall Lee sit on my bed, surprisingly, instead of floating above it. He sighed and took my feet and dragged me out by my feet, taking me by surprise.

"M-Marshall Lee!" I squealed. He turned me around and picked me up into his arms. What the-?! He held me close to him. My head was leaning against his chest as he carried me over to the stairs. I tried to push off of him, but he would just pull me closer. I tried punching him, but my arms were pinned against my sides. I sighed, giving in to his stubborness. I leaned against his chest again, putting my ear on his chest. I suddenly realized, he had no heartbeat.


End file.
